We have a skylight in the roof that allows light to shine through a stained glass feature in the loft floor, through to stairs and landing area. We are just converting the loft and are keeping the stained glass. It was suggested to us that if we cover the glass with clear Perspex, that this can take weight if someone was to stand on it, and it will allow us to still see clearly through the feature?

If you are going to walk on this panel you need to consult a good glass company. The glass needed is a laminated panel utilising one leaf thick annealed glass and one leaf thick toughened.
The toughened glass gives strength and the annealed (NORMAL) glass breaks slower so acts as a safety net giving a bit more time to get off the glass before you fall through it.
The actual spec is dependent on the area of the panel and the method of support.
Perspex is no good as it will scratch in no time.